Step 1: The Project

Step 2: Analysis and Completion

Now after you have successfully wired the USB socket with the PS/2 jack, it's time to test weather the connection were made rightly. Check the continu...

Here i will show you a simple tutorial to convert your USB keyboard to comfortably adapt to a PS/2 connector in a computer.

The Situation I had actually bought a flexible keyboard from the market and i had no idea that it had a USB socket to the output. I was using this USB keyboard for a couple of days and after using it for some time it was giving me trouble. Sometimes the keys did not function properly and sometimes it would automatically eject i.e disconnect from the computer port and again connect. I was having such problem and decided to find a solution for it.

The conception After doing a bit of research i found out that most of the modern keyboards can be easily adapted to a PS/2 connector with ease. The only thing you need is just the USB socket and a PS/2 Jack (i got mine from an old mouse of mine). I also found out that when you buy a keyboard and if it is for the long run like in a Personal Computer, then it is better to have a PS/2 connector bought. Since the flaws for buying a USB keyboard are (i) It is gonna occupy one of the USB slots in your computer and hence there will be no space for USB when you are connecting multiple com ports. (ii)It is gonna use some kind of processor time since it has plugged into a USB. Very nice to have one more empty USB connector Therefore my suggestion for you all if you are buying for a Personal Computer is to buy a PS/2 keyboard in place of USB. But again if you have already bought it then this instructables is gonna teach you how to accomplish the feat.

This will not work. The PS/2 keyboard is like I2C serial device. It has clock and data lines. The hardware inside a PS/2 keyboard doesn't have capabilities to emulate a USB HID device as a USB keyboard. Hence USB will give message device not recognized.

Well Mr. Basak!!I think you have not read my instructables properly. I have already mentioned in my instructable that only some recent usb keyboard can be adapted for this method. And for your information i have already tested in my PC and it is working 100%. you can see the pictures in the instructables given.And thanks for you comment

arupbsk is saying that a PS/2 to USB adapter won't work. He is correct.

You ralkut are arguing that he has not read your instructable properly, but you have in fact not read his comment properly and assume that he is saying that your instructable will not work. He is not. His comment is likely an answer to lukeD's question above.

lukeD, having tried it and researched it I can concur. It does NOT work.

Then it may be because of manufacturers making same COB IC for keyboards whether it is PS2 or USB. Otherwise, theoretically it seems impossible because of different topologies in these two types of keyboards, which prevent them from interchanging interfaces (USB to PS2, or vice versa).

That is correct, and it has nothing to do with how recent the keyboard model is. Most USB keyboards are USB only, but some are USB+PS/2 compatible. It will say on the box if the USB keyboard will work with PS/2, and such keyboards usually come with a plug adapter that performs the same function as this DIY cable.

The information given here, also inadvertently states that if I wanted to Convert a USB to PS/2 Optical mouse that this information would be valid. The reason I ask is I have a Microsoft Comfort Optical mouse 3000. To which I have been using as a PS/2 mouse with the USB to PS/2 Adapter however recently the adapters (two) have stopped functioning. And Using the mouse as USB bothers me because it ejects it's self automatically after about 30 seconds and makes That sound when you eject a device, however once you move the mouse that irritating sound once again emits and begins functioning after a brief pause.

Yes you can if you connect pin No. 4 and Pin No. 3 with a limiting resistor. You can make one. How many Leds you would like to light up by the way. My suggestion is that if you use a single White LED, it would be fine. Just remember PIn No. 4 is positive supply and pin No. 3 is Negative.

Just to know what color of LED would you like to light up. If it is white then the current consumption will be more and i doubt you will heat the system. My suggestion to you is that you try to light up not more than 2 white LED's. And just asking you a question? For what purpose you need the torch for.

Hi i plan on transferring files to an old computer by usb, but it has none. Will it work to transfer files from an mp3 to a computer with this plug? Can this ruin an ipod if I try to sync it with this cable?

That's correct PS/2 jacks have only 4 wires. The color don't matter. You first have to see the continuity of those wires with the jack. Then simply follow the circuit diagram that i have given in the instructable. Many manufactures use different color of wires but you can check it with a simple multimeter and find out the pin outs where these wire lead to.If you look at the diagram that i have posted you can easily connect the keyboard.

That's a Roger. You do indeed have to check the pins one by one and it will take hardly a minute to find out the connections of the wire in the jack.And there are only 4 wires so it will definitely be an easy one.